Electromagnet.



S. G. RHODES. ELECTROMAGNET. APPLICATION FILED FEB. 5, 1916.

Patented May 16,1916.

5] vwewfoz neg I 9 AM 10. F m

or i which SAMUEL or; anonns, on NEW roan, N. assicnofa TO THOMAS E. MURRAY, or NEW N.

ELECTROMAGNET.

wanna-Mm Specification of Letters Patent.

Patented May Mi. 1916.

T 0 all "10.60 m it may concern Be it known that l. SAMUEL G. RHODES, a citizen of the United States, residing at- New York, in the county of New York and State of New York, have invented a certain new and useful Improven'ient in Electromagnets, of which the following is a speci fication.

The invention is an electro1nagnet so constructed that when controlled by a 0111 rent in one direction, the armature is moved to a certain position and there held-when controlled by a current in the other direction, the armature is moved to a certain other position and there held, and when the controlling current is interrupted, the armature remains in whichever position it may stand at the time of the interruption.

In the accompanying drawingsFigure 1 is an elevation of my electro-magnet, the left hand half being in section. Figs. 2 and 3 are diagrams illustrating the, relations of the coils and armature, the armature being shown in two di-iierent positions. F 1g. 4 1s an electrical diagram showlng my electromagnet disposed in a three-wire system and as part oii an apparatus for opemng and closing a lamp circuit from a distant station. e Similar numbers and letters of reference indicate like parts.

The elective-magnet has three coils A, B and C. T he two coils A, B are connect-ed in series and are alike except that they are wound in opposite directions. The coil1C is here wound outside of the coils A. an" B.

i The relation of the coil C to the coils r A is to be such that one half of coil C in ampere turns equals coil A, and the other half equals coil B. But since the coils A, B are wound in reverse directions, themagneti'zing eii'ect of the currentin one coil, as A, will be supplemented by that of the current which is moving in similar direction in coil C, while the magnetizing eflect oi the current in the other coil wound in the opposite direction, as B, will be counterbalanced by the current in coil C. Hence the armature D of the magnet will be'moved in one direction or the other, depending upon the direction of the current in coil 0, and will remain in the po- 'sition' into which it is moved until the current is reveised in coil C. Thus, referring toFigs. 2 and 3, the coil C is divided into halves above and below the broken line 1, 2.

The half 3 which is above line 1. 2 is equal in ampere turns to coil A, and the half 4: which is below line 1, is equal in ampere turns to coil B. The coils A and I) being equal to one another will counterbalance one another, as indicated by the arrows 5, (3. If the current in coil C, as shown in Fig. 2. be in the direction of arrow 7, then obviously the half 3 of coil C will supplement coil A, while the half a of coil C will coun terbalance coil B, and the armature will rise to the position indicated in Fig. 2. If, on

the other hand, the current in coil C be reversed, as shown 1n Fig. 3, and hence in the direction of arrow 8, then the half 4 of coil Q will supplement coil B, while the half 3 of coil C will counterbalance coil A, and the amature will descend to the position indicated in.Fig. 3. Hence by alternately re:

VQZSlllg the current in coil C, the armature 4 D may be moved from one position to the other, and when the current is interrupted to coil C, the armature will remain in the position last taken.

This electro-magnet may be applied to a -S0 great variety of usesas, for example, in telegraphy for the operation of relays, or for controlling light or power circuits from a distance. In Fig. I have illustrated one practical application of it to an apparatus for the control from a distance of a circuit including an electric lamp. I have described and claimed said apparatus in another application for Letters Patent, Serial No.

76,306,-filed simultaneously herewith, and

therefore do not claim said apparatus herein.

Referring to Fig. l: E and G represent the plus and minus potential mains of a three-wire electric light system, F being the neutral main. Said mains are connected to the generators H, I in the usual way. J is an arc lamp connected to the positive main E and the neutral main F. The light circuit contains a switch K which is to be opened and closed to break or make said circuit, and so to extinguish or establish the light at the will of an operator at a distant station K, through the agency of a single conducting wire L leading from said distant station to the place where the lamp is situated. at said distant station X, wire L is connected to the pivot of a bell crank switch lever hL-which lever may be moved into contactw th the terminal of a lead from the positivre'main E or the terminal of a lead the negative main G. The switch ,K is carried by the armature D of th electro-magnet. By moving the switch 5 the distant station to make circuit with flea-d N or O, the current to coil C is alternately reversed; hence switch K is caused to open or close the circuit to lamp J, and after the current is interrupted at switch M, said switch K will remain in its last position. I claim: v

1. An electro-rnagnet, ha ving three coils, two of said coils being wound in relatively opposite'directions and connected in series and each having the samenumber of ampere turns, and the said third coil having ampere Copies of this patent may He obtained for five cents each, by addressing the SAMUEL G. RHODES.

' Witnesses:

GERTRUDE T. PORTER, MAY G. MCGARRY.

Commissioner of Patents.-

Washington, D. 0." 

